London: A teenager from Florida has become the hot topic on the internet after he hitched a ride on the back of a 30ft shark.Chris Kreis, aged 19, grabbed the fin of a whale shark and was pulled through the water for 20 seconds before he let it go.

Kreis was fishing in the Gulf of Mexico when the whale shark swam up alongside his boat. He then dived in and held on to the beast as his friend filmed the annoyed shark try and shake Kreis off.

Marine Biologist, Bruce Neill believed that it wasn't a very good idea. He explained that when people spend a lot of time and pressure on a fish it takes away a slime that covers the fish. They need that layer to stay healthy.

Whale sharks are said to only eat Plankton, Neill said that because they are so large they could inflict some harm inadvertently.